Ocean waves possess very large amounts of kinetic energy of motion that goes almost entirely untapped. Estimates of wave energy potential indicate that it can provide 15-20 times more available energy per square meter than either wind or solar and for the California coastline this amounts to over 7 gigawatts. While there are currently many approaches to harvesting ocean wave energy, they generally employ large, high cost mechanical systems that are expensive to maintain, convert wave energy at low efficiency and pose numerous environmental problems.
Ocean wave energy possesses very high energy density and can provide 15-20 times more available energy per square meter than either wind or solar. Examples of state-of-the-art systems include turbine-type wave energy converters (WECs) and oscillating water columns (OWCs). The OWC operates much like a wind turbine via the principle of wave induced air pressurization and requires an anchoring system to keep the chamber steady for collection of air pressure generated by a wave driven OWC inside the chamber. The overtopping WEC works much like a hydroelectric dam. Waves roll into a collector which funnels the water into a hydro turbine. The turbines are coupled to generators which produce the electricity. The overtopping WEC has to be slack moored or fixed moored to the ocean bottom too. The float-type WEC operates with several different power take-off methods, but all of them involve many mechanical moving parts (e.g. a naturally buoyant float, hose pump, or hinged joint pump) and pose control problems because the wave height may exceed the WEC's stroke length (how far up and down the floater is permitted to move by design). The outcome could be damage to the WEC during a storm when wave heights are extreme. Both current turbine-type and float-type WECs use a generator to convert the kinetic energy to electricity that makes the system large, expensive, low in efficiency, and difficult to maintain. The California Commission Publication #CEC-500-2008-083 (November 2008) “Developing Wave Energy In Coastal California: Potential Socio-Economic and Environmental Effects” and “the Energy Innovation Institute & EPRI Report on Assessment Offshore Wave Energy Conversion Devices” (June 2004) represent comprehensive summaries and assessments of the state-of-the-art in ocean wave energy conversion devices. According to available studies and reports, the ocean wave energy harvesting systems currently being developed generally employ bulky, mechanical equipment that results in cost-inefficiencies, high maintenance, degradation of scenic ocean views and expensive construction. They can also pose a threat to sea navigation and disturb marine life.